New Delhi: The Central Electricity Authority (CEA) has proposed making battery storage and grid-forming inverter capability a construction requirement for Renewable Energy (RE) plants, moving both out of tender conditions and into the technical standards every plant must meet to be built. The draft amendment was published on Thursday for public comments, which close on October 4.
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The proposal inserts a new sub-regulation into the CEA (Technical Standards for Construction of Electric Plants and Electric Lines) Regulations. It states that "the renewable energy power plant which are commissioned after July 1, 2027 shall have at least 15 percent of inverter with grid forming control and all PCS of battery energy storage system shall have grid forming control to comply with the technical requirements as specified in Central Electricity Authority (Technical Standards for Connectivity to the Grid) Regulations." PCS refers to the power conversion system, the electronics that connect a battery to the grid.
The storage obligation comes in two tiers. The first proviso says that "the ground-mounted Solar Power Plant and on-shore Wind Power Plant which are commissioned after 1st July 2027 shall be equipped with co-located Energy Storage System (ESS) having a minimum storage duration of two (2) hours and a capacity equivalent to at least ten percent (10 percent) of the installed capacity of the Plant." The draft illustrates this: "If the Solar Plant is 100 MW, the minimum storage requirement will be 10 MW for 2 Hours."
The second tier doubles the duration. Plants commissioned after July 1, 2029 and up to June 30, 2031 must carry storage of the same 10 percent capacity for four hours. On a 100 MW solar plant, that is 10 MW for four hours.
Both requirements are drawn to cover ground-mounted solar and onshore wind. CEA has retained the power to revise the thresholds, stating that "any change in the percentage of requirement of grid forming capabilities or ESS capacity shall be notified by Authority from time to time."
Conventional solar and wind inverters are grid-following. They detect the voltage waveform the grid already has and inject current in step with it, which means they need a stable reference to work against and cannot supply one themselves. As the share of such plants rises and the share of large spinning machines falls, fewer resources on the system are setting that reference.
Grid-forming inverters establish it. In an advisory issued on July 27 making grid-forming inverters mandatory for upcoming battery storage projects, CEA said such inverters "operate as voltage sources and can actively support grid stability," and that they improve system strength, control power fluctuations and provide black-start support during grid failures. The advisory put their response speed at within five milliseconds of a disturbance, reaching full response within 30 milliseconds.
The draft would give that advisory the force of a regulation for batteries, and extend a smaller obligation, 15 percent of inverters, to renewable plants themselves.
Co-located storage has been applied to Indian solar projects since February 2025, when the Ministry of Power advised all renewable energy implementing agencies (REIAs) and state utilities to include a minimum two-hour co-located ESS equivalent to 10 percent of installed solar capacity in future tenders. CEA subsequently clarified that the requirement applied only to tenders yet to be issued.
That route made storage a condition of a particular procurement. A developer bidding into a tender without the clause, or building outside the central and state tender route altogether, was not bound by it. Placing the same 10 percent and two-hour figures inside the construction standards changes the trigger from the contract to the commissioning date, and the obligation would attach to the plant rather than to the scheme it was sold under.
The regulations these plants would have to comply with are themselves under revision. CEA released draft CEA (Technical Standards for Connectivity to the Grid) Regulations, 2026 on July 31, replacing the 2007 regulations and introducing grid-forming control as a defined term. Comments on that draft closed on September 2.
The draft has been issued under Section 177 of the Electricity Act, 2003. CEA has said that "all the Stakeholders and general public are requested to send their comments on the draft regulations to Chief Engineer (Legal), Sewa Bhawan (North Wing), Room No 622, 6th Floor, RK Puram, New Delhi-110066 by post or through e-mail (celegal-cea@gov.in) latest by 04.10.2026."
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The principal regulations date to December 23, 2022. They were amended on July 3 this year, when CEA notified technical standards for solar, floating solar, onshore and offshore wind plants and battery energy storage systems, coming into force on April 1, 2027. The present proposal is the second amendment to the same regulations this year, and would take effect on the date of its publication in the Official Gazette after consultations are done and a final draft is ready.
